Papers by Dariush Bijani
The influence of wall slip on fluid flow is of interest for many engineering topics involving liq... more The influence of wall slip on fluid flow is of interest for many engineering topics involving liquid-solid interfacial phenomena, such as flow through porous media, liquid coatings and lubrication. Boundary slip can act as a method to reduce friction in lubricated contacts. Furthermore, surface texturing can also play a positive role in enhancing the film thickness. Therefore, a combination of these two methods can be beneficial in order to improve the tribological performance of lubricated contacts. Although the study of frictional behaviour of surfaces with boundary slip has been getting more attention in recent years, the combination of these two methods of surface property modification is interesting to investigate. For the no-slip boundary condition, the first layer of fluid molecules has the same velocity as the contacting solid surface and this condition has been widely applied in the field of fluid mechanics. In lubricated contacts with boundary slip, the first layer of the ...
of contacts to a favourable condition. In this paper, the effect of surface texturing on the film... more of contacts to a favourable condition. In this paper, the effect of surface texturing on the film thickness in parallel sliding surfaces is investigated. It is shown that surface texturing can improve film formation and, as a result, the load-carrying capacity. With the numerical model developed and by taking cavitation into account, the effect of shape, depth, size and textured area fraction on the film thickness is studied. Further, the optimum size for the most beneficial texturing pattern with respect to film thickness is discussed.
The Influence of Surface Texturing on the Frictional Behaviour in Starved Lubricated Parallel Sliding Contacts, 2019
Starvation occurs when the lubricated contact uses up the lubricant supply, and there is not enou... more Starvation occurs when the lubricated contact uses up the lubricant supply, and there is not enough lubricant in the contact to support the separation between solid surfaces. On the other hand, the use of textures on surfaces in lubricated contacts can result in a higher film thickness. In addition, a modification of the surface's geometrical parameters can benefit the tribological behaviour of the contacts. In this article, for parallel sliding surfaces in starved lubricated conditions, the effect of surface texturing upon the coefficient of friction is investigated. It is shown that surface texturing may improve film formation under the conditions of starvation, and as a result, the frictional behaviour of the parallel sliding contact. Furthermore, the effect of starved lubrication on textured surfaces with different patterns in the presence of a cavitation effect, and its influence on frictional behaviour, is investigated. It is shown that surface texturing can reduce the coefficient of friction, and that under certain conditions, the texturing parameter could have an influence on the frictional behaviour of parallel sliding contacts in the starved lubrication regime.
The Influence of Surface Texturing on the Film Thickness in Starved Lubricated Parallel Sliding Contacts, 2018
In industrial applications, a starved lubrication condition may occur, leading to a reduction in ... more In industrial applications, a starved lubrication condition may occur, leading to a reduction in film thickness; by modifying the surface geometry, the tribological performance of the contact is enhanced. In this paper, the influence of surface texturing as a method for reducing the friction on the film thickness in parallel sliding surfaces for starved lubricated contacts is investigated. The results in this study have shown that surface texturing can improve film formation for starved lubricated contacts and, respectively, the load carrying capacity. The effect of starvation on several texturing patterns with several texturing properties was investigated and the film thickness for these conditions was studied. With the numerical algorithm developed and taking cavitation into consideration, the effect of shape, depth, size, and texture pitch on the film thickness was studied.
The Influence of Surface Texturing and Boundary slip on the Film Thickness in Parallel Sliding Surfaces, 2018
Considering the influence of wall slip on fluid flow is important for many engineering topics inv... more Considering the influence of wall slip on fluid flow is important for many engineering topics involving liquid-solid interfacial phenomena, such as flow through porous media, liquid coatings and lubrication. Boundary slip can act as a method to reduce friction in lubricated contacts. Furthermore, surface texturing can also play a positive role to enhance the film thickness. Therefore, combination of these two methods can be beneficial in order to improve the tribological performance of lubricated contacts. Although, in recent years the study of frictional behaviour of surface with boundary slip is getting more attention, the combination of these two methods of surfaces properties modification is interesting to investigate. For the no-slip boundary condition, the first layer of fluid molecules has the same velocity as the contacting solid surface and this condition has been widely applied in the field of fluid mechanics. In lubricated contacts with boundary slip, the first layer of the lubricant molecules move with a different velocity from that of the solid surface. In this article, the frictional behaviour of boundary slip in parallel sliding lubricated contacts for textured surfaces is investigated. This study shows that boundary slip has a significant influence on the film thickness in case of textured surfaces. Furthermore, it is possible to increase the film thickness, and enhance the frictional behaviour by modifying the boundary slip parameters.
The Influence of Surface Texturing on the Frictional Behaviour of Parallel Sliding Lubricated Surfaces under Conditions of Mixed Lubrication, 2018
In many industrial applications, a modification of the surface geometry can enhance the tribologi... more In many industrial applications, a modification of the surface geometry can enhance the tribological behaviour of lubricated sliding contacts. In this paper, the effect of surface texturing on the coefficient of friction in parallel sliding lubricated surfaces is investigated. It is shown that surface texturing can improve film formation and, as a result, the load-carrying capacity as well as a reduction in the coefficient of friction. With the numerical model developed, and by considering cavitation, the effects of shape, depth, size, and the textured area fraction on the frictional behaviour of parallel sliding lubricated contacts under conditions of mixed lubrication is studied. In this article it is shown that the surface texturing can have a beneficial effect, in order to decrease friction.
In many industrial applications, a modification of the surface geometry can enhance the tribologi... more In many industrial applications, a modification of the surface geometry can enhance the tribological behavior of contacts to a favorable condition. In this paper, the effect of surface texturing on the film thickness in parallel sliding surfaces is investigated. It is shown that surface texturing can improve film formation and as a result the load carrying capacity. With the numerical model developed and by considering cavitation, the effect of shape, depth, size and textured area fraction on the film thickness is studied. Further, the optimum size for the most beneficial texturing pattern with respect to film thickness is discussed.
Thesis Chapters by Dariush Bijani
Alle rechten voorbehouden. Niets uit deze uitgave mag worden vermenigvuldigd, in enige vorm of op... more Alle rechten voorbehouden. Niets uit deze uitgave mag worden vermenigvuldigd, in enige vorm of op enige wijze, zonder voorafgaande schriftelijke toestemming van de auteur. to Firouzeh and Mahmoud
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Papers by Dariush Bijani
Thesis Chapters by Dariush Bijani